How to set checkbox always checked when user redirect to another page?

How do I implement my checkbox to stay check as it is even if user redirects to another page? Example, in my code behind when I check the checkbox the system updates the database and it says "Validated" , but when I press GoBackTeacher_Click event it will redirect to another page. In that another page there is a button function there that will redirect to this current page where my code behind function is implemented and checkbox is checked.

Code Behind:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data.SqlClient;
using System.Data;

namespace SoftwareAnalysisAndDesign.SAD
{
    public partial class ValidateSubjectTeacher : System.Web.UI.Page
    {
        CheckBox check = new CheckBox();
        protected void Page_Load(object sender, EventArgs e)
        {
            if (Session["ValidateSubject"] == null)
            {
                Response.Redirect("TeacherPage.aspx", true);
            }

            if (!IsPostBack)
            {
                ValidateSubject.DataSource = Session["ValidateSubject"];
                ValidateSubject.DataBind();
            }
            //Add a checkbox in the last row of GridView Progmatically
            foreach (GridViewRow row in ValidateSubject.Rows)
            {
                check = row.Cells[row.Cells.Count - 1].Controls[0] as CheckBox; //position Check column on last row in gridview
                check.Enabled = true;
                check.CheckedChanged += ValidateSubject_Click; //Bind the event on the button
                check.AutoPostBack = true; //Set the AutoPostBack property to true
            }
        }
        protected void ValidateSubject_Click(object sender, EventArgs e)
        {
            CheckBox chk = (CheckBox)sender;
            GridViewRow grvRow = (GridViewRow)chk.NamingContainer;//This will give row

            string validated = "Validated";
            string notyetvalidated = "Not yet validated";
            string studid = grvRow.Cells[0].Text;
            string coursenum = grvRow.Cells[1].Text;

            if (chk.Checked)
            {
                grvRow.Cells[10].Text = validated;
                //Open Connection
                using (SqlConnection conn = new SqlConnection("Data Source=Keith;Initial Catalog=SAD;Integrated Security=True"))
                {
                    //Open Connection to database
                    try
                    {
                        conn.Open();
                    }
                    catch (Exception E)
                    {
                        Console.WriteLine(E.ToString());
                    }

                    using (SqlCommand cmd = new SqlCommand("Update AssessmentForm set Status = @Validated where StudentID = @studentID and CourseNo = @Coursenumber" ,conn))
                    {
                        cmd.Parameters.AddWithValue("@Validated", validated);
                        cmd.Parameters.AddWithValue("@studentID", studid);
                        cmd.Parameters.AddWithValue("@Coursenumber", coursenum);
                        cmd.ExecuteNonQuery();
                    }

                    //Close Connection to database
                    try
                    {
                        conn.Close();
                    }
                    catch (Exception E)
                    {
                        Console.WriteLine(E.ToString());
                    }
                }
            }
            else
            {
                grvRow.Cells[10].Text = notyetvalidated;
                //Open Connection
                using (SqlConnection conn = new SqlConnection("Data Source=Keith;Initial Catalog=SAD;Integrated Security=True"))
                {
                    //Open Connection to database
                    try
                    {
                        conn.Open();
                    }
                    catch (Exception E)
                    {
                        Console.WriteLine(E.ToString());
                    }
                    //query database to update the Status
                    using (SqlCommand cmd = new SqlCommand("Update AssessmentForm set Status = @Validated where StudentID = @studentID and CourseNo = @Coursenumber", conn))
                    {
                        cmd.Parameters.AddWithValue("@Validated", notyetvalidated);
                        cmd.Parameters.AddWithValue("@studentID", studid);
                        cmd.Parameters.AddWithValue("@Coursenumber", coursenum);
                        cmd.ExecuteNonQuery();
                    }

                    //Close Connection to database
                    try
                    {
                        conn.Close();
                    }
                    catch (Exception E)
                    {
                        Console.WriteLine(E.ToString());
                    }
                }
            }
        }
        protected void GoBackTeacher_Click(object sender, EventArgs e)
        {
            Response.Redirect("TeacherPage.aspx");
        }
    }
}

To further understand my question, here is an image to further explain it.

This is when I check the checkbox without pressing the go back button

And this where I go pressed the go back button and in the another page there is a proceed button to redirect to this current page where my gridview is located.

There the checkbox is unchecked, and the status says it is validated. How do I implement my code that checkbox stay checked?

Is it something to do with postback? Please help.